Engine-valve



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Patented Apr. 8, 1888.

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E. M. HUMSTONE.

ENGINE VALVE. No. 380,325. Patented Apr. 3, 1888.

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E. M. HUMSTONB.

ENGINE VALVE. No. 880,325. Patented'Apr. 3, 1888.

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EDVIN M. HUMSTONE, OF HARTFORD, CONNECTICUT, ASSIGNOR TO JAMES FERGUSON, OF BBIDGEWATER, MASSACHUSETTS.

ENGINE-VALVE.

SPECIFICATION forming part of Letters Patent No. 380,325, dated April 3, 1888.

Application filed February E, 1888. Serial No. 263,379. (No model.)

To @ZZ whom it muy concern:

Be it known that I, EDWIN M. HUMsToNE, of Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Engine Valves, of

which the following is a specification.

My improvement relates to valves for steamengines; and it consists in certain new and improved constructions and combinations of the parts thereof, substantially as hereinafter described and claimed.

In the drawings, Figure lis a top plan view of a steam-chest of a steam-engine with the cover removed, showing the engine-valve and my improved relief valve applied thereto. Fig. 2 is a longitudinal vertical section of the same on the dotted line :v a: of Fig. l. Fig. 3 is a transverse vertical section of Fig. 1 on the line e e. Fig. 4 is a view of a portion of Fig. 2 With the valve removed, showing the reliefvalve in operation when the steam is shut off.

A is the cylinder of the steam engine.

B is the steam-ehest.

C is the valve-cylinder.

vV is the valve.

E is the exhaust chamber.

Steam is admitted to the chest B through the pipe b, and escapes from the exhaustchamber E through the pipe e. The steam-ports c c connect the valve-cylinder C with the engine-cylinder. The construction of these parts is well understood, the balanced valve V being of the kind shown and described in the patent granted to James Ferguson February 9, A. D. 1886, No. 335,571.

Through the top of the valve-cylinder C elongated relief -ports c' c are cut into the steamports cc. I make these relief-ports elongated transversely ofthe valve-cylinder in or der to give them area enough to relieve the engine, as hereinafter described, and keep the steam-ports c c, which surround the valve, narrow in the direction of the length of the valve, which is important, as I thereby have lesslongitudinal reciproeation of the valve and cause it to work quicker. By giving this form to the relief-ports they are also less liable to become clogged with small bits of coal and cinders from the exhaust, While giving suiiicient 5o area to relieve the engine.

On top of the reliefports c' c', I attach the relief-valve D, which is in the form of a plate, covering the ports steam-tight, and capable of rising and falling to open and close the ports. This relief-valve is held in place by the bolts d d, passing through holes in ears on each side of valve D loosely, so as to allo7 it to slide up and down on the bolts. The holes in these ears are slightly elongated in the direction of the axis of valve V. to allow the valve D to tilt 6o or tip as it rises,in the manner shown in Fig. 4.

When the valve and its steam-chest and cylindex' are applied to a locomotive (for which use my invention is intended) and the steam is shut off from the chest B, the driving-wheels of the locomotive drive the piston I? of the cylinder A back and forth in the latter as the engine runs downhill. This exhausts the contents of tl1e-steamehest B out of it at each stroke of the engine piston, and throws such 7o contents, Whether air or steam, into the exhaust E, thus creating a partial vacuum in the chest B, which drags back on the piston P and retards the speed of the locomotive on dovvn grades. This is due to the fact that there is no capacity of the valve V to rise off its seat and relieve this vacuum, asis the case with an ordinary slide-valve held down upon its seat by a spring. By means of the relief-ports c c and relief-valve D this difculty is overcome, 8o as the vacuum in the steamchest B causes the valve to rise off its seat at either end, as shown in Fig. 4, or bodily, as the case may be, and relieves the vacuum either from the ports c c or the exhaustehamber E, or from both. `When the steam is again let on into the chest B, its pressure on top of valve D holds the latter down firmly upon its seat and closes the ports c c steam-tight.

lVhat I claim as new and of my invention 9o l. The combination of the elongated ports c c', opening through the wall of the valvecylinder C into the steam-ports c c, and the valve D, seated over the same and adapted to rise and connect the chest B with the exhaust E, substantially as described.

2. The combination of separate relief-ports opening through the Wall of the valvecylinder C into steam-ports c c, and a single valve, 10o D, covering the same and adapted to rise and relieve the engine, substantially as described.

EDWIN M. HUINISTON E. "Witnesses:

EDWARD D. EoBBINs, C. H. BUNGE. 

